of chicago



I. A. OLSON. POSITIVE GBIPPING CYLINDER. APPLICATIDN FILED APR-15; I918.1,334,503. Patented Mar. 23, 1920.

3 SHEETS-SHEET I- I. A. OLSON.

POSITIVE GRIPPING CYLINDER.

APPLICATION FILED M fl.15,191f3.

' Patented Mar. 23, 1920.

3 SHEETS-SHEET 3- IlI/ll/IIIIIII/ umrnn [snares PATENT cur os.

worm A. OLSON,

OF CHICAGO, ILLINOIS ASSIGNOR TO AMER IOAN PNEUMATIC I C'HUCK COMPANY,OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

POSITIVE-GRIPPING CYLINDER.

To all whom it'd nay concern:

Be it known that I", JOHN 'A. OLsoN, a citizen of the, United 'States'of America, residing at Chicago, in the county of Cook and State ofIllinois, have invented certa n new and useful Improvements in Positive-Gripping Cylinders, of which the following 1s a specification, referencebeing had therein to the accompanying drawlngs This invention relates"to positlve gripping devices and refers more particularly to a grippingcylinder adapted for obtaining increased gripping power for holding thework in lathes or. other rotating devices, although the invention in itsbroader aspectsis not limited to the particular use mentioned.- I

' Among the objects of the invention are to provide a constructionwherein the drawvrod of the gripping member is formed 1n two separateparts, a longitudinal movementof one of which parts produces a lesserlongitudinal movement of the other part;

to provide a construction wherein the work is positively gripped andafter once being locked will be held from release even, though thepressure in the cylinder be reduced to provide a construction whereinless power in the cylinder is requiredfor producing thenecessarygripping action, and which a given movement of thecylinder Wlllpreferably produce a lesser" movement of the plunger rod at the work endof the device; to provide a cylinder of the character above referred tothrough which the work can be extended; to so construct and arrange theinlet passages to the cylinder that power will be applied on both sidesof the shaft; to provide improved packing means for preventing leakagepast the piston; and in general to provide an improved and 81111-plified cogstruction of Q-oliaracter above referred in the drawings:

Figure 1 is a longitudinal sectional view through a device embodying my,invention, parts being shown in elevation;

Fig. 2 is a viewsimilar to Fig. 1 through the work-holding device; a

Fig. 3 is a view similar to Fig. 1 showing a modified construction;

Fig. 4 is a cross-section on the line 1 -4 of Fig. 1. Y

first in detail the constructive gripping c [is as follows: .en theparts are in $119 Specification of Letters Patent. Patented Mar, 23,1920, Application filed April 15, 1918. Serial No. 228,734.

This pisinlet conduit D and the piston B is formed with a hollow passageB one end of which is offset diagonally to one side of the rod B, whileits opposite end is connected to a:

plpe E which extends-through packing E and telescopes with the inletpassageway E The arrangement is such that when it is desired to propelthe piston toward the end G of the cylinder the compressed air isadmitted through the nipple D to the passageway D. This forcesthe pistonto .ward the right where it is held by the compressed air. When,however, it is desired to retract the piston, that is, to move it towardthe left, the compressed air is admitted through the nipple D to thechamber C .on the right hand side of the piston B through the passagewayB. Suitable means (not shown) is provided connected to each of thenipples to permit of the exhaust of the compressed air on either side ofthe piston.

The adjustment or reciprocation of the piston, as above described, isemployed for actuating a chuck or other suitable gripping device asfollows: Extending intothe forward projection or housing 13" is the freeend G of a plunger rod G. This end telescopes over a projection B on theend of the draw rod B. and carries a bearing member H having aring-shaped portion H;

where the cylinder A is non-rotatable the member K is independentlyrotatable on the draw-rod B, but where the whole cylinder revolves withthe work the member 7 K is keyed to the draw-rod'B.

At'its-forward end'the rodG is connected infiap suitable manner to themovable mem bers" of a chuck M or'other-suitable work holding device.The operation of the posilinder as so far described position shown inFigplgthe members L force them have been withdrawn to -the left so as tothe action of the, inclined or b cam surface toward'the center, thusgrip- Ping the spindle'N of thearticle to be M- tated, In this positionthe ends K and K of the levers J and J. have been forced up onto the toof the cam member K and will remain. locged in this position until themovement of the piston B toward the right first releases and thenpositivel forces the ends K- and K toward each ot er. In releasing thework from the position shown 1n 1 ,Fig. 1, compressed air', gas or othersuit- -H on the member H.

able substance is admitted through the inlet D which, acting on thepiston B, forces the draw-rod B- and. projection B? toward the ri ht. Itwill, however, have, no effect upon 51c rod G .(which in reality formsthe second part of'the two-piece draw-rod) until the shoulder O strikesa ainst the shoulder urther movement of the piston toward the ri ht willcarry the member H and rod G' with it so as to cam inember K.

grip ing device toward the left. As the mem ers L ridebeneath theinclined surface I lows:

and J*., In so doing the. levers w the member H toward the left and pullthe shove the movable members L out from beneath the inclined surface Uand thus release the work. However, in moving toward the ri ht, themember H, throu h the action ofr't e rin I-I on the seats will cause theends and K' of; the levers to move down the inclined surface .K of theInthis position the ,work' is released and the device is ready to gripanother piece of work, which gripping action is as fol- Compressed airor other gas is now admitted through the nipple D and passageway E tothe 'ri ht hand side'of the cylinder. This willorce the piston B to moveaway from the wall C and carry with it the rod B and cam member K,the,latter riding beneath the. ends K and K will rock the levers J and Jabout their plivots J 2 1 I adjust rod'Gr and the movable members L ofthe L they will be forced together and tightly grip the work However,owin to the pro- .portioning of the ends of the ever J with reference.to the pivot ,I point, a one-inch movement of the rod B will cause onlya fraction of an inch movement of the pulli rod G. Therefore acomparatively smal cylinder can be employed for operating devices whereconsiderable gripping strength necessary, which arrangement reduces thesize and cost of the gri ping device. 7

"In orderto prevent t e lever from being" ved towardthe rig-htasuflicient distance ress against the spindle end of the ma o m ,in anon-rota le condition, the heel J of the member. J 'jis so arran edthat-it will strike against the member and form a locking device,preventing further movement toward the ri ht. I

It will be notice thatin addition to the packin C and E' previouslymentioned the cylmder is provided with 'a packin P and the piston with at ese packing P packings all being prefera- 1y of esser width at thelunar side than at the outer side and y I inclined outwardly so thatwhen the locking members P are tightened up they will wed the packinginto tight engagement with t e walls and form a very efficient seal. Thedivision between the various parts of the casing of the cylinder A issuch that these this construction are arranged at opposite sides of therjod Q, the assagewa B being extended around to't e rlght hand side ofthe pistonor plun r. 4

Additional packings 5, and S are employed in this construction andintermediate the packin S and S there is interposed a loose col ar Swhich, together with the packings S andS, forms a seal very necessary tothe practical operation of the device. Otherwise the construction shown'm' Fig. 3 is substantially as that shown in 4 Fig. 1, in both cases thecollar S beingemployed. The construction shown in Fig. 3 is particularlyadapted foruse where the article .operated on.-1s of a length whichmakes it necessary to permit it to project through'the' cylinder.Various changes,

however, in the details of construction and arrangements andcombinations of parts can be made within the scope of my invention.

What I claim asmy invention is:

- 1. A positive grippingdevice, comprisingv a cylinder, a piston movablein said cylinder and a draw-rod formed of two sections one of which isconnected to the piston and the other of which is connected to a workholder or the like, and a connection between said sections whereby apredetermined movement. of theplston will, roduce a lesser movement inthe same irection of the section connectedto the work holder.

2. A -ositive gripping device, comprising a cylin er, a iston movable inthe cylinder, a'two-piece raw-rod, one section of/which is qmnected to.the piston and the other section of which is in alinement with saidfirstm'entioned section and connected to the work, a cam memberconnected to the firstmentloned draw-rod section, a lever mechaeaguesnism having a portion arranged to be opf erated on by said cam, and asecond portion arranged to actuate the second section of the draw-rod.

3. A ositive gripping'device, comprismg a cylin er, a iston movable inthe cylinder,

' a two-piece raw-rod, one section of which isconnected to the pistonand the other section of which is connected tov the' work, a cam memberconnected to the first-men'- tioned draw-rod section, a lever mechanismhaving a on by sai cam, and a second portion arranged to actuate thesecond section ofthe draw-rod through'a lesser degree of movement thanand in the same direction as the the like to operate said piston, saidcam member and lever mechanism being arranged to form a lock for holdingthe work independent of the pressure in the cylinder.

5. In a positive gripping device, the combination with a draw-rod havingtwo sec tions, of means for longitudinally moving one of said sectionsin one direction, and means actuated by said section for longitudinallymoving the other of said sections Y in the same direction,saidlast-mentioned (portion arranged to be operated means locking saidother section in one posi-- tion of longitudinal adjustment.

6. A positive rippingdevice, comprisin a grippmg'mem er, a draw-rod forlongitu ina ly adjusting said member, said drawrod being made insections, means for longitudinally moving one oi said sections, andmeans for longitudinally moving another of said sections tion in thesamedirection and at a slower rate of speed.

7. A positive gripping device, comprising a gripping memberand adraw-rod for longitudinally adjusting said member, said draw-rod beingmade in alined sections, means for longitudinally moving one of saidsections, and a lever mechanism for longirom said first-mentioned sec- 1tudinally moving said other section in the same direction from saidfirst-mentioned section, said lever mechanism being arran ed to give alesser movement to said ot er sectlon.

8. In a gripping device, the combination with a gripping member, of adraw-rod for longitudinally adjusting said member, said draw-rod havinga section engaging said member and a second section in alinement withsaid first-mentioned sectiommeans for moving said second sectionlongitudinally n one direction, means for slowly movlng saidfirst-mentloned sectlon 1n the same direction from said second section,and means for moving said second section longitudinally in the op ositedirection, said'second sectlon adapte to abut against saidfirstmentioned section to move the latter.

In testimony whereof I afiix my signature.

JOHN A. oLsoN.

